The present invention relates generally to console air conditioning units and, more particularly, to console air conditioning units that include a plenum and are suitable for both retrofit and new installations.
A typical so-called console package air conditioning unit comprises a single cabinet containing all of the component parts of an air conditioning system needed to heat or cool a specific zone or region within a building, typically a room, such as a school classroom. The console cabinet unit is ordinarily situated next to an outdoor wall of the building, and has an outdoor air access opening through which outdoor air flows in and out via a duct which passes through a corresponding opening in the building wall.
More particularly, within the console package unit are conventional air conditioning components, such as an indoor air heat exchange coil (which functions as an evaporator coil during cooling mode and as a condenser coil during heating mode), as well as an indoor air blower for circulating indoor air over the indoor air heat exchange coil. Additionally, there are an outdoor air heat exchange coil (which functions as a condenser coil during cooling mode and as an evaporator coil during heating mode), and an outdoor air blower for circulating outdoor air over the outdoor air heat exchange coil via the outdoor access opening. The outdoor air blower draws outdoor air in through the outdoor air access opening, passes this air over surfaces of the outdoor air heat exchange coil, and discharges this air out through the outdoor air access opening. Thus, the "outdoor air heat exchange coil" is physically located within the console cabinet and within the building, but functionally is exposed to outdoor air. Correspondingly, the self-contained console package unit is physically inside the building, but functionally is divided into "outdoor" and "indoor" sections.
As the final major component, a refrigerant compressor is connected in a closed refrigerant circuit with the indoor air heat exchange coil and the outdoor air heat exchange coil, as is well known.
In addition to outdoor air drawn in through the outdoor air access opening for circulating over the outdoor air heat exchange coil, in typical installations a certain amount of outdoor air is drawn in for ventilation purposes, and mixed with indoor air circulating over the indoor air heat exchange coil. Thus, the opening in the wall of the building is sized to provide sufficient air for circulation over the outdoor air heat exchange coil, as well as for ventilation purposes.
Console package air conditioning units, like most mechanical devices, require periodic maintenance. Eventually, the components become worn-out, and the entire console package unit is replaced with an identical one. Such replacement is relatively expensive; a replacement unit typically costs $8,000.00. Moreover, replacement console package units usually are nearly identical to the unit being replaced, which may be thirty years old. The replacement units in general have not been re-designed with modern, more efficient refrigeration components.
A significant consideration in replacement applications is that the console package unit is architecturally part of the building or room within which it is installed. Thus, the unit occupies a particular floor area within the building, termed its "footprint", and the opening in the building wall for outdoor air access is sized to accommodate the outdoor air access opening of the console package air conditioning unit. Thus, in situations where a console package air conditioning unit is replaced in its entirety, it is desirable for the replacement unit to be physically of the same size, that is, with the same "footprint" and fitting the same size wall opening, minimizing or eliminating the need for architectural changes in the room.
Also relevant in the context of the invention are prior art outdoor package air conditioning units. An outdoor package air conditioning unit is a self-contained unit, typically including a heat pump system, containing all of the component parts required for heating or cooling air. The outdoor package unit is ordinarily situated outside a building, near a building exterior wall, and connected via duct work, often extending along the exterior wall of the building, in air communication with additional duct work running inside the building and distributing heated or cooled air flow in a conventional manner.
Additional prior art relevant in the context of the subject invention known as a water source heat pump, which is similar to a console package air conditioning unit comprising a single cabinet and containing all of the component parts of an air conditioning system needed to heat or cool a specific zone or region within a building. A water source heat pump differs however in that, rather than an outdoor air heat exchanger, there is an external fluid heat exchanger which provides heat exchange between the refrigeration system of the water source heat pump and an external water loop. The external water loop includes a pump for water circulation, and is connected to a heat sink, such for example an outdoor cooling tower, a buried serpentine pipe ground heat exchanger or a hot water preheater within the building.
Also relevant in the context of the invention are prior art fan/coil units which are rather simple devices comprising basically a blower which passes room air over an indoor heat exchanger, which is supplied with heated or chilled fluid, such as water, from an external chiller and/or heater, which may comprise a large, central air conditioning unit.